Various types of high-performance electronic devices are being developed that use heterojunctions in electronic devices therein made of compound semiconductor crystals such as GaAs. Since the capabilities of these high-performance electronic devices are influenced by the crystallinity of the compound semiconductor crystal included therein, high-quality compound semiconductor crystals are desired. The need for lattice matching at the heterointerfaces in thin film crystal growth for manufacturing electronic devices using GaAs-based compound semiconductor crystals leads to the selection of wafers made of GaAs or of materials such as Ge whose lattice constant is very close to that of GaAs.
Patent Document 1 discloses a semiconductor device that has sections that restrict epitaxial regions grown on a non-matching wafer or a wafer with a high dislocation defect density. Non-Patent Document 1 describes a GaAs epitaxial layer with low dislocation density formed on a Ge-coated Si wafer using lateral epitaxial overgrowth.
Patent Document 1: Japanese Patent Application Publication No. 4-233720